Can't generate message CameraInfo

[ebhrz]

The message type CameraInfo depends on the sensor_msgs, however, in the function in dynamic.py

def _gen_dyn_modify_references(py_text, current_type, types):
...
        for t in types:
                pkg, base_type = genmsg.package_resource_name(t)
                gen_name = _gen_dyn_name(pkg, base_type)
                # - remove any import statements
                py_text = py_text.replace('import %s.msg' % pkg, '')
...

This line will erase the statement of importing sensor_msgs.msg, because the variable pkg here is sensor_msg. Then the message fails to generate.
Does this aim to avoid importing some message type repeatedly?